Algandars is a type of disease in Radiata Stories. It has mysteriously spread throughout the world of Radiata. The disease is fatal to elves, and causes humans to become violent and unstable. When an infected elf dies, their soul also ceases to exist, rather than being passed to another body through the transpiritation ritual.
The first record of the disease is in ancient legend. It happened when a light elf king fell in love with a human woman, whom he then married and bore his child, which is said to be the very first dark elf. Because of this, the elf king became infected with algandars, which later kills him. In fear of the plague, the king sealed up Algandars Castle where he lived with his human bride.
When Ridley is nearly killed by a blood orc, Lord Nogueira performs the transpiritation ritual to save her from death. As a consequence, he develops the disease and perishes from it, according to his brother, Lord Zane, when he is talking to himself near Lord Nogueira's grave.
The actual cause of the disease, according to Ridley during her awakening, is the imbalance in Tottaus. The reason it is beginning to spread in both races is because of the slayings of the dragons, and the eventual awakening of the Gold Dragon. She also states that Lord Zane is infected with the disease as well. During the Human Side playthrough, after defeating Lord Zane at the battle of Lupus gate, he is mortally wounded and, he succumbs to the disease and dies.
During the Nonhuman Side playthrough, the ruins of Algandars Castle are explored by Jack at the request of Mikey, a dark elf who dreams of the day when humans and elves can live together without the fear of algandars. Accordng to Mikey, the only victims of algandars are humans and elves. There is no reference of it affecting other races such as dwarves, blood orcs, or green orcs. Exploring the castle doesn't yield any results of a cure for the disease; only that the light elf king would have given up everything for his love. This seems to cement Jack's resolve to help Ridley through her journey until the end. Little information is gained after the exploration of Algandars Castle during the Human Side playthrough.
- It is speculated that the word "algandars" is derived from the word "algae", as the effects of the disease in light elves looks very similar to that of algae growing on their body.